IT is VERY COMMON for the radio in an RV to be wired hot
this is SO you do not have to turn on the key to have music while parked
it is usually wire to the house batteries not the engine/chassis battery
generator can be wired to either house or chassis batteries my personal preference is generator connected to engine/chassis battery,
so you can still start the genny with out the aux jump start ,IF you ran down the house batteries while camping
while camping on shore power or generator power, a single jumper cable from house positive to chassis-engine positive will maintain and charge the engine battery ( or install a 'Trik-L-start' )
if using generator power for charging remember to remove the jumper when you shut down the genny
sounds like all the batteries are weak and no longer have much capacity left
and bleed down from internal shorts when sitting, and are ready for replacement
